Support for accurate and reliable location of a mobile device in an indoor environment such a building, subway or venue is being developed but is currently not widely available nor as accurate or reliable as needed by applications, users and venue and building owners. Support for security and privacy in the context of in-building location is also at an early stage of development. For example, support for in-building location security and privacy, with the solution being developed by the In Location Alliance (ILA) is very limited. For example, several ways exist in which a mobile device (MD) can spoof a media access control (MAC) address of another MD in order to obtain the spoofed MD's location without authorization or to feed false location information to a location client of the spoofed MD. In the ILA architecture, there are three separate over-the-air (OTA) interfaces to an MD on which different MD identifiers (IDs) can be used. Verifying on a network side of the architecture that the same MD is at the end of each interface may be difficult.